Australian marine environments are unique because of their long period
of isolation and the length of the coastline facing the southern oceans.
number of species that are found only along the southern coasts si very
high. Some 85 percent of fish species, 95 percent of molluscs and 90 percent
of echinoderms are restricted to these southern temperate seas. Our southern
coastline also supports one of the largest numbers of marine flora, with
more than 1,100 species of red algae alone - 25 percent of the world total,
75 percent of which are endemic.
Australia has a large range of coastal habitats and marine ecosystems,
from the rough rocky coasts of the south-east and west to the calmer-water
seagrass and mangrove habitats of the gulf regions.
uniqueness is due largely to its long period of geological isolation (in
contrast with tropical Australia) and the long ice-free east east-west
extent of the southern coastline.
isolation of SA has produced some of the highest levels of biodiversity
and uniqueness (or endemism) in the world. For example approximately 95
percent of all fish, echinoderms and molluscs found in these temperate
waters are found nowhere else in Australia, and nowhere else in the world.
By comparison, endemism in tropical fauna is approximately 10-15 percent.
the high levels of marine biodiversity and endemism in these regions,
however, temperate marine environments remain some of the most under-researched
and poorly protected environments in Australia.